| /** |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package org.apache.hadoop.io.serializer; |
| |
| import java.util.ArrayList; |
| import java.util.List; |
| |
| import org.apache.commons.logging.Log; |
| import org.apache.commons.logging.LogFactory; |
| import org.apache.hadoop.conf.Configuration; |
| import org.apache.hadoop.conf.Configured; |
| import org.apache.hadoop.util.ReflectionUtils; |
| import org.apache.hadoop.util.StringUtils; |
| |
| /** |
| * <p> |
| * A factory for {@link Serialization}s. |
| * </p> |
| */ |
| public class SerializationFactory extends Configured { |
| |
| private static final Log LOG = |
| LogFactory.getLog(SerializationFactory.class.getName()); |
| |
| private List<Serialization<?>> serializations = new ArrayList<Serialization<?>>(); |
| |
| /** |
| * <p> |
| * Serializations are found by reading the <code>io.serializations</code> |
| * property from <code>conf</code>, which is a comma-delimited list of |
| * classnames. |
| * </p> |
| */ |
| public SerializationFactory(Configuration conf) { |
| super(conf); |
| for (String serializerName : conf.getStrings("io.serializations", |
| new String[]{"org.apache.hadoop.io.serializer.WritableSerialization"})) { |
| add(conf, serializerName); |
| } |
| } |
| |
| @SuppressWarnings("unchecked") |
| private void add(Configuration conf, String serializationName) { |
| try { |
| |
| Class<? extends Serialization> serializionClass = |
| (Class<? extends Serialization>) conf.getClassByName(serializationName); |
| serializations.add((Serialization) |
| ReflectionUtils.newInstance(serializionClass, getConf())); |
| } catch (ClassNotFoundException e) { |
| LOG.warn("Serilization class not found: " + |
| StringUtils.stringifyException(e)); |
| } |
| } |
| |
| public <T> Serializer<T> getSerializer(Class<T> c) { |
| return getSerialization(c).getSerializer(c); |
| } |
| |
| public <T> Deserializer<T> getDeserializer(Class<T> c) { |
| return getSerialization(c).getDeserializer(c); |
| } |
| |
| @SuppressWarnings("unchecked") |
| public <T> Serialization<T> getSerialization(Class<T> c) { |
| for (Serialization serialization : serializations) { |
| if (serialization.accept(c)) { |
| return (Serialization<T>) serialization; |
| } |
| } |
| return null; |
| } |
| } |